Crewmembers of the American container ship Maersk Alabama speak to the media at the Kenyan coastal sea port of Mombasa, 500 kilometres from the capital Nairobi, on Monday after the release of Capt. Richard Phillips. (Antony Njuguna/Reuters)

Three U.S. naval snipers each fired a single shot to kill a trio of pirates holding an American cargo ship captain hostage on a lifeboat in the Indian Ocean, the head of the U.S. Naval Forces Central Command said Monday.

In an interview with NBC's Today show, Vice-Admiral William Gortney said "extremely, extremely well-trained" Navy SEAL snipers were able to make the shot from the stern of the nearby USS Bainbridge at night in rolling waters.

Officials made the decision to shoot after military spotters on the Bainbridge saw one of the pirates holding an AK-47 rifle close to the head of Capt. Richard Phillips on Sunday.

The U.S. navy released a photo of Maersk Alabama Capt. Richard Phillips on the USS Bainbridge after being rescued by navy SEALS off the coast of Somalia. (U.S. navy/Associated Press)

Phillips was taken hostage last week when Somalian pirates attacked the U.S.-flagged Maersk Alabama off the Horn of Africa in the Indian Ocean. It was delivering a cargo of food aid to Somalia and Uganda.

Four pirates escaped on a lifeboat with Phillips as a hostage.

The SEALS arrived on the scene by parachuting from an aircraft into the sea and were picked up by the Bainbridge, which was patrolling the waters near the lifeboat, a senior U.S. official said.

Gortney said the snipers fired simultaneously when the heads and shoulders of the pirates were all exposed at the same time.

The fourth pirate, who is reportedly about 16 to 20 years old, surrendered and is in American custody.

Phillips' wife said her husband praised the military for rescuing him and called them the "real heroes" of this ordeal.

Obama proud of military

U.S. President Barack Obama said Monday he was proud of the military for rescuing Phillips. The president, who approved the deadly sniper shots, said the captain's safety was his administration's main concern throughout the crisis.

"I want to be very clear that we are resolved to halt the rise of piracy in that region and to achieve that goal, we're going to have to continue to work with our partners to prevent future attacks," he said.

"We have to continue to be prepared to confront them when they arise, and we have to ensure that those who commit acts of piracy are held accountable for their crimes."

Somalian pirates have vowed retaliation for the killings, raising fears for the safety of about 230 foreign sailors still held hostage in more than a dozen ships anchored off the coast of lawless Somalia.

In Mogadishu on Monday, mortars were fired toward the city's airport as a plane carrying a visiting U.S. congressman lifted off. Officials at the airport said New Jersey Democrat Donald Payne was not injured and that none of the six mortar shells landed in the airport.

Payne, who is chairman of the House of Representatives Foreign Affairs subcommittee on Africa, met with Somalia's president and prime minister during his one-day visit to discuss piracy, security and co-operation.

Lucky to be alive, says crew

Shane Murphy and other crew members of the Maersk Alabama wave to reporters during their press briefing Monday. (Karel Prinsloo/Associated Press)

Earlier Monday, the crew of the Maersk Alabama called on Obama to use American resources to end the Somalian pirate "scourge."

"At sea, it's a global community. We live together, we look out for each other. America has to be at the forefront of this. It's a crisis, wake up," said the ship's chief officer, Shane Murphy, during a brief news conference in Mombasa, Kenya.

"This crew was lucky to be out of this with every one of us alive. We're not going to be that lucky again."

Murphy, who commanded the ship after Phillips was taken, said they spoke with the captain by phone.

"It was an extremely emotional experience for all of us. He's absolutely elated. He was proud of us for doing what he trained us to do," he said.

"Everybody here today has Capt. Phillips to thank for their lives and freedom."

Murphy wouldn't give any details about the attempted hijacking, but said all crewmembers are working with FBI and coast guard investigators.

"We won't describe what happened. There are ships right now under attack. These men have valuable knowledge that can save lives," he said.

"We ask you not to press us for details about things like that."

Crew looking forward to U.S. return

When they reached Mombasa on Saturday, crewmembers said Phillips told them to lock themselves in a cabin while he surrendered himself.

The crew said they are looking forward to returning to the U.S. and reuniting with friends and family.

A dozen warships from countries including Britain, France, Germany, Iran and the United States now dot the notorious waters in the gulf in an attempt to deter pirate attacks.

With files from the Associated Press